1. Field of the Invention
The present invention relates to a pattern reading apparatus capable of displaying optical patterns such as characters, symbols or designs by a tactile display device provided with a plurality of vibrating pins, causing vibration corresponding to said pattern.
2. Related Background Art
In the field of the pattern reading apparatus of this kind, the Japanese Patent Kokoku 56-46854 already discloses an apparatus which converts an optical pattern, read through a camera unit, into electrical signals and displays said pattern by vibration of a bimorph tactile array of matrix structure, and which is already utilized as a reader for blind persons.
However such a conventional pattern reading apparatus has a fixed frequency for reading the pattern, and therefore generates significant flickering or beat in the read pattern, in case of reading a pattern displayed on an optical display device having a frame repeating cycle, such as a cathode ray tube or a liquid crystal display device.